Technology of Drilling Deep Directional Wells in Qingxi Oilfield

Drilling deep directional wells in the Qingxi Oilfield have met a series of difficulties, such as well bore quality controlat vertical sections, low rate of penetration (ROP) at build section and well trajectory control, etc. In order to solve these problems, trajectory control and drilling rate improvement in deep complex section were studied. Through the analysis of regional geologic characteristics and drilling difficulties technical research and design were conducted to achieve trajectory control at inclined section and drilling rate improvement.An ROP improvement test was conducted with a torque impacter at the hold section, and the trajectory control and ROP test were adopted for mid-low speed and high-power PDM tools, combined withhigh impact and abrasion resistant five-blade PDC bits as well as high-accuracy MWD. This technique was applied in 4 directional wells and an average ROP at deviation sections increased by 74.65%. The results indicated that it met the requirement of trajectory control,while the shortest directional drilling duration was 59.00 days,directional drilling average time was 89.79 d. At the end, there was a reduction of 45.88% in the drilling time versus conventional ways. It was demonstrated that the combined technology of high-efficiency PDC bits, low-speed high-torque PDM tools, MWD and torque impacters had a better result in trajectory control and ROP improvement in deep directional drilling in Qingxi Oilfield. Based on the positive results, it is recommended that the new techniques be promoted and applied in this area.